Supplementary Figure-1. SDS PAGE analysis of purified designed carbonic anhydrase enzymes. M1-M4 shown in lanes 1-4, respectively, with molecular

Transcription

1 Supplementary Figure-1. SDS PAGE analysis of purified designed carbonic anhydrase enzymes. M1-M4 shown in lanes 1-4, respectively, with molecular weight markers (M).

2 Supplementary Figure-2. Overlay of the crystal structures of the four mutants (purple) and the wild type (yellow). M1-M4 are represented in purple and the WT in yellow. The loop regions where small amounts of variability can be seen are indicated by red circles.

3 Supplementary Figure-3. Electron density maps of selected mutated residues in M1-M4. Three residues are shown in each panel: n-1, n and n+1 around the mutation. 2mFo-DFc electron density maps are shown at the 1.5 sigma level. (a) n = D36 in M1 and (b) n = D57 in M2.

4 Supplementary Figure-3 (continued). Electron density maps of selected mutated residues in M1-M4. Three residues are shown in each panel: n-1, n and n+1 around the mutation. 2mFo-DFc electron density maps are shown at the 1.5 sigma level. (c) n = E238 in M3 and (d) n = D86 in M4.

5 Supplementary Figure-4. Thermal unfolding analysis for WT and M1-M4 carbonic anhydrases. Experiments were performed in the presence of increasing millimolar concentrations of ionic liquids (a) Ethyl-AF (b) Ethyl-NO 3 and (c) DMI-DMP. For each enzyme, thermostability is indicated by the difference in thermal unfolding value (T h ) obtained by DSF in the presence of ionic liquid and 50 mm Tris-HCl ph 8.5 versus buffer only. Supplementary Figure-5. Thermal unfolding analysis of WT and M1-M4 carbonic anhydrases. Experiments were performed in the presence of increasing millimolar concentrations of denaturants (a) urea and (b) guanidinium hydrochloride. For each enzyme, thermostability is indicated by the difference in thermal unfolding value (T h ) obtained by DSF in the presence of denaturant and 50 mm Tris-HCl ph 8.5 versus buffer only.

6 Supplementary Figure-6. Circular dichroism analysis of WT and M4 preincubated in SDS. Percentage α-helix and β-sheet secondary structure content in WT and M4 carbonic anhydrases incubated for 1 h with increasing concentrations of the detergent sodium dodecyl sulfate (SDS) in 10 mm Tris-HCl ph 8 added prior to circular dichroism analysis. Supplementary Figure-7. Circular dichroism analysis of WT, M3 and M4. Absorbance spectra taken in the presence of guanidinium hydrochloride ( M) in 10 mm Tris-HCl ph 8 as determined by circular dichroism spectroscopy at (a) 220 nm and (b) 222 nm.

7 Supplementary Figure-8. Relative 4-nitrophenyl acetate esterase activity of WT and M1 - M4. Activity measured by spectrophotometry at the isosbestic point for 4-nitrophenol, 348 nm, at three different ph points. Activity for each enzyme is shown as percentage activity relative to the value measured at ph 8 for each enzyme. Supplementary Figure-9. Effect of the addition of GuHCl (mm) on 4-NPA esterase activity of WT, M3 and M4. Control activity refers to the activity of the individual enzyme in the assay buffer only.

8

9

10

11 Supplementary Figure-10. Radius of gyration and RMSD plots for the MD production periods for WT and M4.

12

13 Supplementary Figure-11. Radial distribution functions (g(r)) from the MD simulations for Na + and each of the mutated residues in M4 for the NaCl system. The blue traces depict the first 250 ns of the production period and the blue traces depict the subsequent 250 ns.

14 Supplementary Figure-12. Radial distribution functions (g(r)) from the MD simulations for Na + and each of the mutated residues in M4 for the NaNO 3 system. The blue traces depict the first 250 ns of the production period and the blue traces depict the subsequent 250 ns.

15 Supplementary Figure-13. Radial distribution functions (g(r)) from the MD simulations for Na + and each of the mutated residues in M4 for the NaHSO 4 system. The blue traces depict the first 250 ns of the production period and the blue traces depict the subsequent 250 ns.

16 Supplementary Figure-14. ClustalW alignment of 50 amino acid sequences of closest relationship to bovine carbonic anhydrase II NP_ by BLASTp analysis. Sites within the protein considered to be tolerant of variation were selected based on their degree of substitution in related enzyme sequences and selection as a residue for mutation was made also on the basis that they were occurred on the surface of the protein. These residues are indicated in the query bovine carbonic anhydrase sequence in the top line of the alignment.

17 Supplementary Figure-14 (continued). ClustalW alignment of 50 amino acid sequences of closest relationship to bovine carbonic anhydrase II NP_ by BLASTp analysis. Sites within the protein considered to be tolerant of variation were selected based on their degree of substitution in related enzyme sequences and selection as a residue for mutation was made also on the basis that they were likely to occur on the surface of the protein. These residues are indicated in the query bovine carbonic anhydrase sequence in the top line of the alignment.

18 Supplementary Figure-14 (continued). ClustalW alignment of 50 amino acid sequences of closest relationship to bovine carbonic anhydrase II NP_ by BLASTp analysis. Sites within the protein considered to be tolerant of variation were selected based on their degree of substitution in related enzyme sequences and selection as a residue for mutation was made also on the basis that they were likely to occur on the surface of the protein. These residues are indicated in the query bovine carbonic anhydrase sequence in the top line of the alignment.

19 Supplementary Table 1. Molecular weight (MW) and amino acid content of carbonic anhydrases WT and M1-M4. Amino WT M1 M2 M3 M4 acid MW 29,300 29,379 29,279 29,358 29,390 Ala Cys Asp Glu Phe Gly His Ile Lys Leu Met Asn Pro Gln Arg Ser Thr Val Trp Tyr Supplementary Table 2. Summary of the IC50 values for NaNO 3 against the 4-NPA esterase activity of WT and M1-M4. 4-NPA WT M1 M2 M3 M4 (mm) Mean 81.6 a b 81.2 a c d s.e.m Sodium nitrate concentrations of between 50 and 3000 mm were tested at each concentration of 4-NPA. Different lower case letters on mean values denote those that are significantly different from each other at p<0.05 in a Student s t test.

20 Supplementary Table 3. Pertinent system parameters for each of the MD simulations. WT (NaCl) WT (NaNO 3 ) WT (NaHSO 4 ) M4 (NaCl) M4 (NaNO 3 ) M4 (NaHSO 4 ) Volume (A3) 681, , , , , ,048 Total water molecules 18,059 16,594 17,327 17,087 15,949 18,554 Total atoms 58,487 54,482 57,286 55,505 52,481 60,556 Subspace overlap a a Overlap of the eigenvectors of the backbone atoms between the first and second halves of the 500 ns production period of the MD simulations